This invention relates to a microwave coffee brewing appliance of the percolation type. It is adapted to be used within the cavity of a microwave oven to brew coffee in a relatively short time by comparison with conventional coffee brewing methods. Conventional percolators are designed for stove top use or contain an internal heating element. The stove top variety is designed to be placed over a heat source which heats the bottom of the percolator and delivers much of the heat to water confined beneath the domed base of the percolator pump. Those with an internal heating element are constructed so the heating element directly heats the water below the domed base of the percolator pump. This placement of the heat source or heating element below the base of the percolator pump enhances percolation pump action in a fashion not available in a microwave oven.
Microwave coffee makers have been made in the past for making coffee by other methods, such as shown and described in U.S. Pat. No. 2,601,067 to Spencer which discloses a coffee maker with a lower sealed chamber with a tube from the upper chamber projecting downwardly into the lower chamber. When the water in the lower chamber is heated, steam pressure pushes the water upward through the coffee particles into the upper chamber. When the water is cooled, it flows back down through the coffee in a two pass process similar to the one pass drip process.
Another microwave coffee maker for microwave use is disclosed in U.S. Pat. No. 4,104,957 to Freedman et al, which shows a drip-type coffee maker with upper and lower chambers with the water in the upper chamber and the coffee in a filter basket between the two chambers. Upon reaching the desired temperature, the water flows down through a temperature activated valve in a one pass drip process.
The only other known use of microwave heating for making coffee and which has been commonly used is to boil water in a microwave oven for use in making instant coffee.
None of these structures or methods for use in microwave ovens produces coffee by percolation, with the distinctive taste imparted by percolation, or with the flexibility of the percolation process whereby variation of the percolation time will change the strength of the brewed coffee.